CO 4 Denial Code: Avoiding Denials

Why I am getting CO 4 Denial?
CO 4 Denial Code: The procedure code is inconsistent with the modifier used or a required modifier is missing. You are receiving this reason code when a claim is submitted and the procedure code(s) are billed with the wrong modifier(s), or the required modifier(s) are missing. A clear understanding of the carrier’s rules and regulations is necessary in order to assign the appropriate modifier(s) correctly. You might receive Remark Code N519 (Invalid combination of HCPCS modifiers). Let us see below the example to understand the CO 4 denial code.
Assume the provider has performed the electrical stimulation procedure (invasive) to aid bone healing.
We have to report the claim with the procedure code 20975. If suppose provider submits this procedure code along with modifier 51, then the claim will be denied as CO 4 Denial Code. Because as per CPT book guidelines for procedure code 20975 modifier 51 is exempted, so we should not report procedure code 20975 with modifier 51.
Next Step
First review and check to see with the coding team that the used modifier is in-consistent or required modifier is missing. Update the appropriate modifier and resubmit the claim (Some insurances, claims should be resubmitted as a corrected claim). You can reach the claims department with the following questions to resolve the below denial:
- Get the Claim received date and denial date.
- First verify whether submitted modifier is invalid or any modifier is missing.
- Check the application to verify other date of service of the same patient, to see same procedure codes with or without modifier were paid previously. If yes send the claim back for reprocessing. If no, check with representative and try to get appropriate modifier missing or the valid modifier for that procedure code. If rep provides, update and resubmit the claim as corrected claim.
- If rep doesn’t provide, get the appeals details/corrected claim address and time limit to resubmit the claim as corrected claim. (Note: Send this to coding team to review and take necessary action as per their suggestion).
Researching and resubmitting claims with common denial codes like CO 4 denial code can lead to long, frustrating hours trying to figure out why the claim was denied in the first place. The good news is that on average, 63% of denied claims are recoverable and nearly 90% are preventable. E2E Medical Billing Services can assist you in addressing these denials and recover the insurance reimbursement. For more information, feel free to call us at 888-552-1290 or write to us at info@e2eMedicalBilling.com